1. Technical Field
The present invention relates to a feeding device including a feeding roller (which picks up stacked recording medium and feeds them downstream) and a pair of transport rollers (which transport the fed recording medium to a recording section), and to a recording apparatus and to a liquid ejecting apparatus including the feeding device.
Here, “liquid ejecting apparatus” not only refers to recording apparatuses, such as a facsimile, a copying machine, and an ink jet recording apparatus performing recording on a recording medium, such as a recording sheet, by ejecting ink onto the recording medium from a recording head serving as a liquid ejecting head, but also to an apparatus that adheres a liquid to an ejection medium (corresponding to the recording medium) by ejecting to the ejection medium a particular-purpose liquid instead of ink from a liquid ejecting head (corresponding to the aforementioned recording head). Examples of liquid ejecting heads include, in addition to the recording head, a color-material ejecting head used in producing a color filter of, for example, a liquid crystal display; an electrode-material (conductive paste) ejecting head used for forming electrodes in, for example, an organic EL display or a surface emitting display (FED); a bioorganic material ejecting head used for producing a bio-chip; and a sample ejecting head, serving as a precision pippet, that ejects a sample.
2. Related Art
As discussed in JP-A-2000-318881, a related feeding device includes a hopper, where sheets are stacked; a feeding roller that picks up the topmost sheet among the stacked sheets and feeds it downstream; and a pair of transport rollers that transport the fed sheet to a recording section. More specifically, the hopper is provided so that its upper portion swings on a fulcrum and so that it moves into contact with and separates from the feeding roller. In addition, the hopper is provided so that, when it moves close to the feeding roller, the feeding roller rotates and picks up the topmost sheet. Further, the hopper is provided so that, even when a plurality of sheets are picked up, the sheets are separated by a separating unit, as a result of which only one sheet is fed to the pair of transport rollers.
An example of a related feeding device is shown in FIGS. 5A and 5B. FIGS. 5A and 5B are side sectional views of the related feeding device. Of these figures, FIG. 5A shows tangent lines, one being situated at a contact point of a feeding roller and a retard roller and the other being situated at a nip point of a pair of transport rollers. On the other hand, FIG. 5B shows a state in which a sheet is fed between the feeding roller and the pair of transport rollers.
As shown in FIGS. 5A and 5B, a related feeding device includes a feeding roller 501, which is D-shaped as viewed from a side; a retard roller 508 serving as a separating unit and provided so that it can externally contact the feeding roller 501; and a pair of transport rollers 504 that transport a sheet P1 to a downstream recording section (not shown). The pair of transport rollers 504 include a transport drive roller 505, which performs driving by driving force, and a transport driven roller 506, which is driven and rotated by rotation of the transport drive roller 505).
Between the feeding roller 501 and the pair of transport rollers 504, a guide 509 that supports the bottom of the sheet P1 being fed and that guides the sheet P1 to the pair of transport rollers 504 is provided at a base side. A path top portion 503 is provided at a holder 502 side so as to oppose the guide 509.
In the related art, as shown in FIG. 5A, between a contact point 510 of the feeding roller 501 and the retard roller 508 and a nip point 511 of the pair of transport rollers 504, a first tangent line U at the contact point 510 of the feeding roller 501 and the retard roller 508 intersects a second tangent line W at the nip point 511 of the pair of transport rollers 504.
Therefore, as shown in FIG. 5B, when the sheet P1 is fed from the feeding roller 501 to the pair of transport rollers 504, the sheet P1 is bended so as to protrude towards the intersection point with respect to a line F connecting the contact point 510 and the nip point 511 and serving as a boundary. This takes place between the contact point 510 of the feeding roller 501 and the retard roller 508 and the nip point 511 of the pair of transport rollers 504. In addition, during what is called “skew removing,” the sheet P1 is further bended between the contact point 510 of the feeding roller 501 and the retard roller 508 and the nip point 511 of the pair of transport rollers 504. Therefore, as shown by a chain line, a sheet P1′ is bended in accordance with a shape of a receding section 512 that recedes downward or upstream and that is formed at the guide 509, which corresponds to a side of the intersection point.
However, since the guide 509 is formed so that the sheet is bended in accordance with the receding section 512 at the guide 509, for providing a bending amount during skew removing, the receding amount of the receding section 512 of the guide 509 needs to be large. When the receding amount of the receding section 512 is large, the rigidity of a base 513 may be reduced.
In addition, there is a limit as to how large the receding amount can be made while maintaining the function of guiding the sheet P1 to the pair of transport rollers 504, which is a function of the guide 509. Therefore, since the sheet P1 cannot be bended by a large bending amount, skew removing may not be satisfactorily carried out.
Further, a space at the side of the path top portion opposing the guide 509 is what is called a dead space 507.